Typewriter



J. C. REDDICK.

TYPEWRITER.

APPLICATION FILED APR=28. 1921.

1,4014 Patented Feb. 21, 1922.

whit? n stares JOEE GGA'ISWOR'IH REDDICK, F TORONTO, ONTARIO, CANADA.

ryrnwairnn.

lineman.

Application filed April 28, 1921. Serial Ito. 465,199.

T 0 all whom it may concern.

e it known that I, Join: Conrswonrn RrpnIoK, subject of the King of Great Britain, and residing in thecity of Toronto, in the county of York, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Typewriters, of which the following is the specification.

My invention relates to improvements in typewriters and the object of the invention is to devise means whereby an ordinary typewriter may be utilized for cutting stencils without removing the platen which is used for ordinary typing purposes or detrimentally affecting such platen by the stencil cutting operation and it consists essentially of the arrangement and construction of parts as hereinafter more particularly explained.

Fig. 1 is a front elevation of the carriage and platen of the typewriter showing my device applied thereto.

Fig. 2 is a vertical section through Fig. 1.

Fig. 3 is a similar view to Fig. 1 showing a modified construction.

Fig. 4: is a vertical section through Fig. 3.

Fig. 5 is a perspective view through a portion of a platen showing another modification of my device.

Fig. 6 is a sectional view through Fig. 5.

In the drawings like characters of refer- 1( since indicate corresponding parts in each ure.

Referring to Figs. 1 and 2-1 indicates a portion of a typewriting carriage. 2 indicates a platen. which is mounted on the carriage in the usual manner. 3 is a rod which extends across the carriage above and parallel to the platen, 4 and 5 are arms carried upon the rod 3 andconnected together by cross rods 6, 7 and 8 and forming'a supporting frame. The rod (5 is turnably mounted at its ends in the arms 4 and 5. Upon the rod 6 is mounted a roller 9, having an annular groove 10. 11 is a sheet of thin flexible material in strip form which may be of metal, celluloid, or any other suitable substance. The sheet strip 11 is passed around the platen 2- so as to be in contact therewith at the printing point of the platen. 12 and 13 are orifices formed at the end of the strip 11. 14 is a band of elastic material such as elastic tape provided at its ends with hooks 15 and 16. The band 14 passes around the roller 9 within the groove 19 and the hooks 15 and 16 engage the perforation 13 and 14. By this means a tension is exerted on each end of the strip 11 pulling it tight around the platen so that it hugs the surface thereof and has close contact therewith at all points of engagement. Such flexible sheet strip may cover all or a portion of the printing surface so that when writlng on paper or other material or cutting stencils such strip will form a protecting surface between the type and the ordinary platen or writing surface. At the same time the strip will travel or turn with the platen when spaced around for a new writing line so that all parts exposed to the action of the keys are equally protected against the action of the keys.

' In Figs. 2 and 4 I show a modified construction in which the sheet strip is formed endless as indicated at 17. In order to maintain the tension upon the strip so as to hold it in close contact with the platen as described in connection with Figs. 1 and 2, I have provided supplemental arms 18 and 19 swung upon the arms 4* and 5 and between which is journalled a roller 20 which bears upon the upper surface of the strip 17 between the platen and the supporting roller 21 which takes the place of the roller 9 referred to in Fig. 1. The roller 20 is spring held in contact with the strip 11 by springs 22 or by any other means adapted to exert spring pressure upon the roller and to exert tension upon the strip 17 to draw the strip tight around the platen and hold it in close contact therewith. The roller 21 is provided with end flanges 23 to serve as guiding means for the strip. In this form it will be seen that not only is tension exerted upon the strip but the strip travels with the platen when the platen is spaced around for a new writing line.

In Figs. 5 and 6 I have shown a further modification. In this form the strip 24 of thin metal, celluloid or other .material is placed around the platen and is provided at its ends with perforations 25 and 26. 27 are bands of elastic material or other tension means provided at their ends with hooks 28 and 29 which engage with the perforations 26 so as to draw the strip 2% tightaround the roller and over the printing point so as to provide a hard even and firm surface, conforming to the face of the platen. It has been found that the operation of the cutting stencils on an ordinary platen will very quickly wear it out and necessitate its renewal in a very short space of time.

' her like compound of which the ordinary typewriter platen is formed. As these platens are costly it makes the cutting of stencils by this method very expensive. In order to avoid this, hard platens such as brass platens have been used but by the employment of these the type is quickly worn out and must be re laced involving not only great expense but oss of time in the use of the typewriter during the makin of such repairs, as such a platen is very d ifiicult to remove from the machine and remains permanently therein. It will also be seen that no feed rollers are necessary to make the ,flexible strip rotate with the platen on account of the fact that the band is at all points under tension and clings to the platen and rotates with it without the necessity of extra feed rollers. This is an important point because inthe use of a band for cutting or stencilling addressin stencil plates the band ma be made a-tri e less in width than the'wi th of the stencil plates themselves so that the stencil plates will retain the full effect of the usual feed rollers that grip and make the stencils feed either up or down into the printing position. This is a very desirable feature as it helps to keep the stencils from slipping which would at times happen if they had to feed in contact with a shiny or smooth surface.

I am aware thatpiecesof celluloid have been used clamped to the platen by a curved frame which snaps on through being made of spring'y metal but such devices grip and bend stencils and make them unfit to work in the automatic feed of an addressing machine and furthermore the small celluloid strip is not under tension and has a tendency to bulge thereby causing the cutting of imperfect outlines in the stencil. The metal frame which holds such celluloid strips in a stationar position on the platen also interferes wit the paper feed'mechanism of a typewriter.

From this description, it will be seen that I have devised a very simple means of forming a hard, even and firm backing surface interposed between the keys of a typewriter and the surface of the platen which will be free from bulge at all points and effectually protects such surface from injury during the cutting of the} stencil and insures a clean cuttin of the stencil and at the same'tir'ne provi es a backing which moves with the great many more copies than could be pro duced when the ordinary soft platen is used.

What 'Iclaim as my invention is:

1. In a t pewriter, the combination with the cylindrical platen, of a backing formed by a sheet of hard flexible material wrapped around the outside of the platen, and elastic or resilient tension means connected to the free edges of the sheet adapted to exert a constant stretch in the sheet to automatically take up surface expansion produced therein by key impact at the printing point.

2. In a t pewriter, the combination with the cylindrlcal platen, of a backing formed by a sheet of hard flexible material wrapped around the outside of the platen, and means connected to the free edges of the sheet adapted to exert a pull in a substantially parallel direction towards the inner side of the platen to exert a stretch and thereby in a self acting manner producing even tension to take up surface expansion therein produced by key impact to draw the portion tending to bulge by expansion into contact with the platen and to maintain it in contact therewith. a

3. In a typewriter, the combination with the cylindrical platen, of a backing formed by a sheet of hard flexible material adapted to wrap around the outer face of the platen and to expand past the inner side of such platen in a substantially parallel direction, and means rovided to. exert a constant automatic ta e up whereby the slack is taken up in the expanded surface to produce a close contact between the sheet and the front peripheral portion of'the platen.

4. In a typewriter, the combination with the typewriter carriage and cylindrical platen, of a frame mounted upon the platen, a cross support mounted upon the frame, a sheet strip of hard flexible material adapted to be looped around the platen over the printing point, and a tension band detachably connected at the ends to the loop and passing freely over the cross support.

5. In a ty )ewriter, the combination with the typewriter carriage and cylindrical platen, ofa frame mounted upon the car riage, a cross support mounted upon the frame, a sheet strip of hard flexible material adapted to be looped around the platen over the prmting point and having a perforation in proximity to each end, and a tension band extending freely over the cross support and provided with end hooks engaging the perforations of the sheet strip.

6. In a typewriter, the combination with a typewriter carriage and cylindrical platen, of a frame mounted upon the carriage above the platen, a roller mounted upon the frame provided with an annular groove, a sheet strip of hard, flexible material adapted to be'looped around the platen over the printing point, and a tension band moaee o connected at the ends to the loop andp'assing around the roller within the annular groove thereof.

7. In a typewriter,' the combination with a typewriter carriage, and cylindrical platen, of a frame mounted upon the carriage above' the platen, a roller mounted upon the frame provided'with an annular groove, a sheet strip'of hard, flexible'material adapted to be looped around the platen over the printing point, and a tension band detachably connected at the ends to theloop and passing around the roller within the annular groove. thereof.

8. In a typewriter, the combination with' a typewriter carriage, and cylindrical platen, of a frame mounted upon the carforation in proximity to each end and a tension band extending around the roller within the groove thereof and provided with endhooks engaging the perforations of the sheet .strip.

JOHN 'COATSWORTH REDDIOK.

Witnesses:

M. lPrroHER, F. M. BARDEN. 

